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<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script type="text/javascript">
		// var a="";
		// var b=10;
		// console.log(a&&b);

		// console.log(!b);
		/*

		1.  false ""....-->""-->boolean-->


		*/
		



		var a=10;
		var b={
			name:'lisi',
			age:20,
			valueOf:function(){
				return 12
			},
			toString:function(){
				return b.name+b.age
			}
		}
		console.log(b.toString());
		// console.log(b.valueOf());
		/*var sum=a+b;
		console.log(sum);
*/



		/*var tr=`
		<tr>
			<td>tom</td>
			<td>12</td>
			<td></td>
			<td></td>
		</tr>`;

		console.log(tr);*/


	</script>
</head>
<body>
	<tr>
		<td></td>
		<td></td>
		<td></td>
		<td></td>
	</tr>
</body>
</html>